Tungsten oxide powder slurry, method of producing the same, and method of producing an electrochromic device using the same

Abstract

According to one embodiment, provided is a tungsten oxide powder slurry in which a tungsten oxide powder and an aqueous solvent are mixed. D 50 is 20 nm to 10000 nm and D 90 is 100000 nm or less in a particle size cumulative graph of the tungsten oxide powder in the slurry. According to X-ray diffraction, a half-value width of a most intense peak detected at 29°±1° is 2° or less.

What is claimed is: 
     
         1 . A tungsten oxide powder slurry comprising:
 a tungsten oxide powder; and   an aqueous solvent,   D 50  being 20 nm to 10000 nm and D 90  being 100000 nm or less in a particle size cumulative graph of the tungsten oxide powder in the slurry, and   a half-value width of a most intense peak detected at 29°±1° being 2° or less according to X-ray diffraction.   
     
     
         2 . The tungsten oxide powder slurry according to  claim 1 , wherein D 50  is 500 nm or less, and D 90  is 1000 nm or less. 
     
     
         3 . The tungsten oxide powder slurry according to  claim 1 , wherein a particle size frequency graph of the tungsten oxide powder has one peak within a range of Do to D 90 . 
     
     
         4 . The tungsten oxide powder slurry according to  claim 2 , wherein a particle size frequency graph of the tungsten oxide powder has one peak within a range of Do to D 90 . 
     
     
         5 . The tungsten oxide powder slurry according to  claim 1 , wherein a content of the tungsten oxide powder in the slurry is within a range of 5% by mass to 50% by mass. 
     
     
         6 . The tungsten oxide powder slurry according to  claim 3 , wherein a content of the tungsten oxide powder in the slurry is within a range of 5% by mass to 50% by mass. 
     
     
         7 . The tungsten oxide powder slurry according to  claim 1 , comprising one or more selected from ammonia, potassium hydroxide, or sodium hydroxide. 
     
     
         8 . The tungsten oxide powder slurry according to  claim 3 , comprising one or more selected from ammonia, potassium hydroxide, or sodium hydroxide. 
     
     
         9 . The tungsten oxide powder slurry according to  claim 1 , wherein the tungsten oxide powder without the aqueous solvent has an average particle size of 20 nm or less. 
     
     
         10 . The tungsten oxide powder slurry according to  claim 3 , wherein the tungsten oxide powder without the aqueous solvent has an average particle size of 20 nm or less. 
     
     
         11 . The tungsten oxide powder slurry according to  claim 1 , comprising a tungsten oxide powder comprising 0.01% by mass to 50% by mass of any one or more of potassium, sodium, lithium, or magnesium. 
     
     
         12 . The tungsten oxide powder slurry according to  claim 1 , wherein an absorbance at a wavelength of 600 nm is 1 or less. 
     
     
         13 . The tungsten oxide powder slurry according to  claim 6 , wherein an absorbance at a wavelength of 600 nm is 1 or less. 
     
     
         14 . The tungsten oxide powder slurry according to  claim 1 , wherein a ratio, absorbance at wavelength 350 nm/absorbance at wavelength 600 nm, is 3 or more. 
     
     
         15 . The tungsten oxide powder slurry according to  claim 12 , wherein a ratio, absorbance at wavelength 350 nm/absorbance at wavelength 600 nm, is 3 or more. 
     
     
         16 . A slurry for producing an electrochromic device, the slurry comprising the tungsten oxide powder slurry according to  claim 1 . 
     
     
         17 . A method of producing an electrochromic device, the tungsten oxide powder slurry according to  claim 1  being used to produce the electrochromic device. 
     
     
         18 . A method of producing the tungsten oxide powder slurry according to  claim 1 , the method comprising:
 grinding the tungsten oxide powder with a bead mill using beads having a particle size of 0.05 mm to 0.5 mm; and   mixing the ground tungsten oxide powder with the aqueous solvent.   
     
     
         19 . The method of producing the tungsten oxide powder slurry according to  claim 18 , wherein each of the beads contains 50% by mass or more of zirconium oxide.